Are anxiety and depression really separate disorders?
Dr Simone Forlee and Dr Lynne Drummond examine diagnosis and treatment
There may be considerable overlap in the presentation of anxiety and depressive disorders. People suffering a depressive episode may have both physical and cognitive symptoms of anxiety, such as agitation or worries about their health.
Anxiety combined lethargy may give a similar picture to that of agoraphobia or social phobia. Equally, co-morbid depression commonly ensues in patients with anxiety disorders.
Some argue that the distinction between anxiety and depression is somewhat artificial.
We need to make as accurate a diagnosis as we can, however, because there are implications for length of treatment with medication and appropriate referral for psychological therapies.
If there is any doubt about what came first, it is always wise to treat the depression first and then re-evaluate any symptoms that remain.
This syndrome includes not only the affective state of a patient, such as low mood, but also characteristic cognitive, physical and behavioural components, including:
· Consistently low mood, often worse in the morning; mood may vary, but rarely returns to pre-depressive level
· Sleep disturbance, with early-morning wakening being more prevalent in severe depression
· Reduction in appetite, weight loss, constipation
· Loss of libido.
At least two weeks' duration is required before we can call these symptoms a depressive episode. The 21-item Beck Depression Inventory, a self-completion questionnaire, gives an indication of clinical severity and can be repeated regularly to monitor response to treatment.
Current opinion is that there is often a genetic susceptibility the risk of developing depression is 1.5-3 times greater if one has a first-degree relative affected. Life events and trauma may trigger the onset of depressive disorder. Once this has occurred, biochemical imbalances in the neurotransmitter systems are induced and perpetuate the low mood.
Some 60 per cent of patients respond to a trial of antidepressant medication, which increases to up to 80 per cent when a second drug is tried after initial drug failure. In someone who suffers from recurrent depression or where the risk of a recurrent episode outweighs the risk of continuing medication, medication may be considered for the indefinite future.
People vary in their response to antidepressants and ability to tolerate side-effects. Unfortunately there is no way to predict who will respond to which specific drug, but a good starting point is to use the same drug if there has been a previous good response.
The most commonly used antidepressants are of course selective serotonin reuptake inhibitors. Newer antidepressants, such as reboxetine, mirtazapine and venlafaxine, have the advantage of relatively fewer antimuscarinic side-effects and, crucially, far less cardiotoxicity in overdose when compared with older tricyclic antidepressants and monoamine oxidase inhibitors. TCA-related antidepressants such as trazadone, mianserin and moclobemide offer alternative choices.
Cognitive therapy has been shown to benefit patients with mild to moderate depression and also to prevent relapse; this treatment needs to be performed by a trained therapist. Self-help books are available but the vast majority of patients will not succeed without considerable support from a therapist. There is little firm evidence to suggest other forms of psychotherapy are useful in any but the mildest of conditions.
St John's wort (hypericin) is a popular lay alternative treatment for depression but it has controversial efficacy and is not subjected to the standards of conventional medicines.
Anxiety disorders are listed on the right. They can be treated using antidepressants and anxiolytics, as well as psychological therapies. SSRIs have been shown to have good efficacy, but treatment requires higher doses of SSRIs than those used for depression. It may also take longer for therapeutic effects to be gained.
In terms of panic disorder and GAD, SSRIs may need to be started at lower doses because patients tend to be more prone to short-term worsening of panic when starting antidepressants. In general, symptoms tend to recur once medication is discontinued.
The problem is therefore the dilemma of starting people, often in early adult life, on long-term medication. Drugs such as SSRIs have not been available for the 50-plus years that they may need to be taken, so no one knows what long-term side-effects may be.
It also means taking drugs during a period when many patients may be starting a family, again with possible severe consequences. Benzodiazepines may have a short-term role in patients with GAD, panic disorder and social phobia.
Psychological treatment for anxiety disorders has the advantage of no side-effects; also it often confers longlasting benefit. The basis of successful treatment for most anxiety disorders is graduated exposure in real life to the feared situation. This may require the guidance of a trained therapist. Very high levels of anxiety or panic may ensue in someone with a phobic disorder. This may arise in anticipation of the fear-provoking situation and as such it seems sensible to treat the phobia primarily. This is controversial, however, with some arguing that panic has a separate biological basis and thus should be treated differently.
The ICD-10 and DSM 4 classification systems differ in this regard. According to ICD-10 the phobic disorder takes precedence and so the usual management is a behavioural approach to address the phobia primarily. A cognitive component also has a role: psycho-education as to the effects of hyperventilation in producing symptoms of panic may be helpful, as may be challenging faulty beliefs and teaching slow-breathing techniques.
Social phobia has been the most extensively studied phobia with regards to psychopharmacology and cognitive therapy. Exposure therapy works well if the fear is just of a small component of social activity, for example eating in public. Some people may have a more generalised phobia to all social situations. This may have had its onset in adolescence, leading to avoidance of social situations and thus preventing normal development of social skills.
In such cases social skills training either individually or in groups is necessary before attempting real-life exposure. Cognitive therapy is more useful than in the other phobic disorder, as the patient may have adopted a range of safety behaviours. Cognitive therapy can be used to help encourage them to abandon these safety behaviours.
In the absence of a trained therapist, some patients can also successfully use self-help books. There are also telephone and computer treatment programmes, which can be used by some individuals with mild to moderate difficulties.
Lynne Drummond is consultant psychiatrist at
St George's Medical School, London
Simone Forlee is senior house officer, Springfield University Hospital, London
· Symptoms usually only start to improve after two to four weeks of an adequate dose
· Side-effects, particularly with the newer antidepressants, are typically transient if present, they tend to wear off within the first week or two
· Medication should not be stopped abruptly without first discussing it with the GP
· Full remission may take up to four months
· It is advisable to continue medication for at least a year after resolution to prevent relapse
· Medication will usually need to be weaned off over a period of four to eight weeks
· Recovery is typically a 'saw tooth' curve, with a few good days interspersed with bad days; the number of good days increases while the bad days grow fewer
Obsessive-compulsive disorder characterised by recurrent intrusive, distressing thoughts, impulses or images relieved by anxiolytic stereotyped rituals or compulsions
Agoraphobia includes situations in which there is perceived to be no easy escape route
Panic disorder recurrent and discrete episodes of extreme anxiety accompanied by physical symptoms such as palpitations, sweating, breathlessness, tingling, as well as cognitions such as 'I'm going mad/going to die/having a heart attack'
Social phobias an exaggerated fear of scrutiny or evaluation by others, leading to avoidance of public speaking, eating, drinking, signing one's name in public, meeting strangers, dating or attending parties
Specific phobias a morbid fear out of proportion to the threat of the stimulus
Generalised anxiety disorder unexplained generalised increase in anxiety, may be
accompanied by physical or emotional symptoms
Hypochondriacal disorder cognitive model similar to OCD, where medical reassurance acts as an anxiolytic ritual
Post-traumatic stress disorder involves the repeated reliving of the trauma in the form of dreams or 'flashbacks' on a background of persisting 'numbness' or detachment; accompanied by avoidance of reminders of the trauma and a state of hypervigilance and hyperarousal
·Self-help book on depression: Greenberg D, Padesky CA. Mind Over Mood. New York: Guilford Press: Basic Books; 2000
·Self-help book on anxiety: Marks, IM. Living with Fear. New York:
1 Fineberg N, Drummond LM. Anxiety disorders: drug treatment or behavioural cognitive psychotherapy? Medical Progress 1996; April:11-16
2 Bandelow B et al. Obsessive-compulsive and post-traumatic stress disorders. World J Biol Psychiatry
3 Australian and New Zealand clinical practice guidelines for the treatment of panic disorder and agoraphobia.
Aust NZ J Psychiatry 2003;37(6):641-56